grithens



2 Sheets-Sheet 1.

(No Model.)

JQ. C. GITHENS. `Steam Rook Drill.

Patented Oct. 19, |880.

N. PETERS, FHDTOLITMOGRAPMER. WASHINGTON. D CV (No Model.) 2 Sheets-Sheet 2.

J. c.. GITHBNS. Steam Rook Drill.

No. 233,501. Patented Oct. 19,1880.

NAPERS, PMOTDvLITNOGRAPHER, WASHXNGTON. D C.

' UNITED STATES PATENT OFFICE.

JOSEPH O. GITHENS, OF NEW YORK, N. Y., ASSIGNOR TO RAND DltlLli COMPANY, OF SAME PLACE.

STEAM ROCK-DRILL.

SPECIFICATION forming part of Letters Patent N0. 233,501, dated October 19, 1880.

Application filed July 8, 1880. (No model.)

To all whom 'it 'may concern:

Be it known that I, JOSEPH (J. GITHENS, of the city and State of New York, have invented certain Improvements in Steam Rock-Drills, of which the following is a specification.

My improvements relate to the class of steam rock-drills in which the rotating feed motion is imparted to the piston which carries the drill by means of a spiral guide-rod, which engages a nut fixed centrally in the end of the piston. As the piston reciprocates this nut traverses the spiral guide-rod, and either imparts a rotary motion thereto or derives a rotary motion therefrom, accordingly as the spiral guiderod is itself left free to rotate or is prevented from rotation by friction exerted upon its head by means of steam-pressure. This friction upon the head of the guide-rod is exerted by means of live steam introduced into the bottom or extreme inner end ot' the cylinder, where it acts either upon a supplemental piston or upon a diaphragm, which is thus made to bear upon the head of the spiral guide-rod and hold it iirmly upon its seat during the inward movement of the piston which carries the drill. In operation, however, there is a rebound of the drill at each blow, which enlarges the live-steam space beneath the piston and correspondingly contracts the exhaust-steam space between the inner end of the piston and the piston or diaphragm which bears upon the head of the spiral guide-rod. It thus sometimes happens that the steam-pressure in the exhaust-space exceeds the steam-pressure upon the supplemental piston or diaphragm, and by lifting the latter frees the head of the guiderod from friction. The guide-rod is thus permitted to rotate instead of remaining stationary, and causing the rotation of the piston carrying the drill.

It is the object of my improvements to overcome this difficulty and my present invention consists, mainly, in combining with the steamchamber, between the bottom of the cylinder and the supplemental piston or diaphragm, which, for convenience, l call the supplemental steam-chamber,7 a check-valve which yields inwardly to admit steam into the supplemental steam-chamber, but closes in case the pressure in the live-steam space beneath the drill-piston is diminished by the rebounding of the drill.

In order to open the check-valve and permit the escape of steam from the supplemental steam-chamber I provide the check-valve with a lateral arm, which projects so far into or across the supplemental steam -chamber as to be struck and be lifted by the supplemental piston or diaphragm at the conclusion of the upward stroke ofthe drill-piston, when the supplemental piston or diaphragm is acted upon by live steam introduced into the cylinder between the drill-piston and the supplemental piston or diaphragm. Steam is thus introduced just before the conclusion of the upward stroke of the drill-piston, and is given access to the inner face of the supplemental piston or diaphragm through longitudinal perforations in the head of the spiral guide-rod and the seat upon which the head of the guiderod bears.

In the accompanying drawings, representing a steam rock-drill embodying my improvements, Figure l is a central longitudinal section through the drill-cylinder, showing the supplement piston, the head of the spiral guiderod and its seat, and a portion of the drill-piston in section, and showing the spiral portion of the guide-rod and a portion ofthe drill-piston in elevation, this section being taken through the line zo w on Fig. 2. Fig. 2 is a transverse section through the line x :c on Fig. l. Fig.3 is a central longitudinal section of a portion of the d rill-cylinder through the line y y on Fig. 2. Fig. 4 is a transverse section of the drillcylinder through the line z z on Fig. 3.

The drawings represent my improvements applied to a steam rock-drill like that described in Letters Patent of the United States No. 158,060, granted to me, for improvements in steam rock-drills, December 22, 1874.

The drill-cylinder A is provided with suitable valve-gear', by means of which steam 1s alternately admitted through the steam-passages B and C, into the steam-spaces B' and C', for the purpose of acting upon the opposite ends, respectively, of the drill-piston D. The inner portion of the drill-piston is longitudinally recessed to admit the spiral guide-rod Q, which is engaged by the nut R, centrally affixed to IOO the inner end of' the drill-piston. The spiral guide-rod Q isprovided with an annular ilange, q, which hasits bearing upon the annularshonlder q',attixed to the interior ot' the cylinder A. This shoulder also forms the seat for the head S of the spiral guide-rod. The head S is a perforated disk secured upon the upper einl ot' the spiral guide-rod by the liam-nut S.

The shoulder q' is provided with longitudinal perforations f and the annular groove q, for the admission, at thc proper time, ot' live steam through thc pert'orations .sin the head ofthe spiral guide into the space between the head S and the supplemental piston T. The supplemental piston is provided with a transverse key-rib, T', which is engaged in a corresponding groove formed across the inner i'ace ot' the cap U ot' the cylinder. this construction is to prevent the supplemental piston from rotating, and the key-rib T is therefore made suliiciently high and its groove suiijciently deep to provide for the reciprocatioii of thc supplemental piston without the disengagement otthe key-ri b T t'rom its groove.

The supplemental piston is acted upon b v live steam introduced into the supplemental steam-chamber T-I through the steam-passage b, which receives its supply ot' steam l'roin the principal steam-passage ll. The supplemental steam-chamber 'l`2 would be in constant communication with the steam-sparc Il hut for the check-valve li. The stem eot' the check-valve is provided with an expanding spiial spring,

c', which is made to yield by the pressure ot' live steam in the passage I; upon the valve li. thus permitting theopemngot the valve li and the introduction ot' live steam into the supplemental steam-chamber T2.

It will be seen that by this mode ot organization tite check-valve will drop upon its seat if', after the introduction ot live steam into the supplemental steam-chamber T-, there is any diminution ot' pressure in the steam-space and consequently in the steam-passages I3 and b, such as may arise from the rebounding ot" the drill. By the closing ot' the check-valve the steam pressure upon the supplemental piston T, and consequently upon the head S of the spiral guide-rod, will be persistently maintained until the instant when the drillpiston concludes its upward stroke aml live steam is introduced into the steam-space (7, t0 effect the downward stroke ot' thc drill-piston. At this instant the pressure ot' the steam in the steam-space C', acting through the passages q2 ando upon the under side ot the stipplemental piston T, will raise the supplemental piston. carrying up the arm li', projecting laterally inward i'rom thc check-valve l. thus opening the check-valve and allowing the eX- haust-steam to escape t'rom the supplemental chamber T2.

During the downward movement ol' the drill-piston tite spiral guide-rod will be t'ree to rotate owing to the absence ot' steam from the supplemental steam-chamber T2 and the con- Tlie object otsequent absence of pressure upon the head S ot' the guide-rod. Just before the conclusion ot' the downward stroke of the drill-piston live steam is admitted into the steam-space B' through thc steam-passage B, and hence through the steam-passage b into the supplemental chamber T2, thus again causing the downward movement of' the supplemental piston l and the application ot' friction to the head S ot' the guide-rod.

The supplemental piston T is, it will be seen, a clatnp worked by steam, and its automatic operation as a steam-clamp for the head ofthe spiral guide-rod is rendered much more certain and etectual bythe presence of the check-valvel which I have described, and also ot' the device in the nature of a key, which prevents the possibility of its own rotation.

lt will ot' course be understood that the cheek-valve may, it' desired, be opened at the conclusion ot' each upward stroke of the drill b v a positive motion derived directly from the drill-piston or from the drill piston-rod and transmitted b v means of a sliding rod, the thrust ol' which would be received either upon the laterally-proiecting arm E or upon a, laterally-projecting tappet affixed to tite checkvalve stein c. in which latter case the checkvalve stem c might be lengthened and made to extend through the end or cap U of the cylinder, so that thc lateral tappet could be aiiixed to it externally. 0n account of its greater simplicity, however, I prefer the form ot' construction shown in the drawings, in which the thrust which opens the check-valve is delivered upon the arm E', which projects into tite supplemental steam-chamber.

I claim as my invention in a steam rockdrill substantially such as describedl. In a steam rock-drill, the supplemental steam-chamber T2 and the steam-passage b, provided with the springr check-valve E, in combination with the steam-space B' and the drill-piston l), substantially as set forth.

1.. In a steam rock-drill, the spiral guiderotl Q, in combination with the supplemental piston T, the key-rib T', and its seat, for the purpose ot preventing the rotation ofthe supplemental piston, substantially as described.

3. In a steam rock-drill, the check-valve E, provided with thc lateral projection E', for receiving the thrust by which the spring checkvaive is opened at the conclusion of each upward stroke of thc drill-piston D, as set, forth.

4. In a steam rock-drill, the combination ot' theI cylinder A, the drill-piston D, and the steam-passages B and C with the supplemental piston T, thel friction-plate S, and spiral guide-rod Q, the steam-passage b, and the spring cheek-valve E, substantially as described.

JOSEPH C. GITHENS.

Witnesses:

M. L. ADAMS, EDWD. IAYSON.

IIO 

